Triggering Cancer in the Unborn

Cancer from fetal carcinogen exposure depends on dosing and timing

(RxWiki News) Can an unborn child be exposed to cancer causing agents while in its mother's womb? Will the cancer develop over time and appear later in life? New research says that indeed this is possible.

Being exposed to carcinogens while still in the womb can cause a number of different problems much later in life, including cancer. The nature of these problems depends on the timing and levels of exposure.

"Enjoy clean, fresh air and food during your pregnancy."

The animal studies were conducted by scientists in the Linus Pauling Institute at Oregon State University (OSU) and other institutions. Researchers tested various types of carcinogens during different stages of pregnancy.

Exposure to toxins causes so-called epigenetic changes in cells. That is, the gene expression in the cells are altered.

For the study, the mice were given four separate doses of one type of polycyclic aromatic hydrocarbon (PAH), a group of compounds commonly found in air pollution and everything from automobile exhaust to coal combustion.

The levels of exposure were far higher than humans would be normally encounter.

The study mice developed ovarian cancers at three times the expected level when they reached middle age. Nearly 80 percent had lung cancer and many of the males had abnormally small testes.

Previous research found that mice exposed to the same amount of carcinogen in a single dose had significantly more  T-cell lymphoma, a kind of blood cancer.

David Williams, a professor of environmental and molecular toxicology at OSU, says fetuses are much more sensitive than adults for a number of reasons.

"But it's interesting that the timing of fetal exposure makes such a difference in which organs are targeted. These results were somewhat surprising," he said.

dailyRx Contributing Expert, Emanuel F. Petricoin, Ph.D., professor and co-director of the Center for Applied Proteomics and Molecular Medicine at George Mason University, explained, "These epigenetic changes manifest themselves as changes in the protein 'circuitry' of the cells, which then program the cell to do things it's not supposed to, such as keep growing when it should be quiet, or turn off proteins that ensure the DNA replicates correctly, etc."

Petricoin said, "Once these changes occur they can be hard wired into the cell for many generations and cause a domino effect that turns normal cell function into a deranged disease state."

Findings from this study were published in the journal Cancer Letters.

Reviewed by: 
Review Date: 
December 21, 2011